清洁催化氧化苯甲醛制备苯甲酸

以过氧化氢作为氧化剂,Na2WO4·2H2O作为催化剂来催化氧化苯甲醛制备苯甲酸。选用与催化剂等物质的量的NaHSO4·H2O作添加物,分别考察反应时间,催化剂的物质的量对苯甲酸收率的影响。反应产物通过测熔点、红外光谱来分析。得出反应的最佳实验条件为:回流温度下,n(苯甲醛)／n(Na2WO4·2H2O)／n(添加物)／n(过氧化氢)为100:1:1:250,反应时间为5 h。改变添加物的种类,进一步对23种添加物对苯甲酸收率的影响进行了考察。结果表明,在最佳实验条件下,选择对甲苯磺酸为添加物时,苯甲酸收率达84.05％。

Clean Synthesis of Benzoic Acid by Catalytic Oxidation of Benzaldehyde

Using hydrogen peroxide as an oxidant, and Na2WO4 · 2H2O as catalyst to catalyze the oxidation of benzaldehyde to benzoic acid, NaHSO4· H2O( n (Na2WO4 · 2H2O): n ( NaHSO4 ·H2O ) = 1:1) as the promoter was chosen, and the effect of reaction time and catalyst dosage on the yield of benzoic acid were studied. The product is determined by melting point and infrared spectrometry. The best reaction conditions is: the mole ratio of n (benzaldehyde)/n (Na2WO4 ·2H2O)/n (additive)/n(hydrogen peroxide) = 100:1 : 1 :250, refluxing 5 h. Furthermore, the best additive is p - toluenesulfonic acid through the observation of 23 kinds of additives. Under the best reaction reaction conditions, the yield of benzoic acid can get 84.05% .